There has been known an information processing system for outputting an image containing a character string to a display unit. For example, in an electronic commerce system that implements a virtual shopping mall where a plurality of stores are open, an item image prepared by a store is displayed on a display unit of a user terminal. In such an electronic commerce system, there may be a case in which a character string indicating a special privilege, such as “free shipping” etc., for example, is added to an item image (see FIG. 13 in Patent Literature 1, for example).